U.S. patent application number 16/740573 was filed with the patent office on 2020-05-14 for personal care compositions with two benefit phases.
The applicant listed for this patent is The Procter & Gamble Company. Invention is credited to Brent William MASON, Scott William SYFERT, Shannon Dale WAGERS, Karl Shiqing WEI.
Application Number | 20200146967 16/740573 |
Document ID | / |
Family ID | 54602068 |
Filed Date | 2020-05-14 |
United States Patent
Application |
20200146967 |
Kind Code |
A1 |
WEI; Karl Shiqing ; et
al. |
May 14, 2020 |
Personal Care Compositions With Two Benefit Phases
Abstract
Methods of enhancing deposition of a high viscosity benefit
agent can include manufacturing a personal care composition
comprising the high viscosity benefit agent and a low viscosity
benefit agent by adding the high viscosity benefit agent and the
low viscosity benefit agent separately to a cleansing phase.
Inventors: |
WEI; Karl Shiqing; (Mason,
OH) ; SYFERT; Scott William; (Fort Mitchell, KY)
; WAGERS; Shannon Dale; (Liberty Township, OH) ;
MASON; Brent William; (West Chester, OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
The Procter & Gamble Company |
Cincinnati |
OH |
US |
|
|
Family ID: |
54602068 |
Appl. No.: |
16/740573 |
Filed: |
January 13, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14937425 |
Nov 10, 2015 |
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16740573 |
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62077690 |
Nov 10, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61K 8/31 20130101; A61K
8/8152 20130101; A61K 8/92 20130101; A61K 8/922 20130101; A61Q
19/10 20130101; A61K 8/73 20130101; A61K 8/90 20130101; A61Q 19/00
20130101; A61K 8/375 20130101 |
International
Class: |
A61K 8/81 20060101
A61K008/81; A61K 8/92 20060101 A61K008/92; A61K 8/37 20060101
A61K008/37; A61K 8/31 20060101 A61K008/31; A61Q 19/10 20060101
A61Q019/10; A61Q 19/00 20060101 A61Q019/00; A61K 8/73 20060101
A61K008/73; A61K 8/90 20060101 A61K008/90 |
Claims
1. A method for enhancing deposition of a high viscosity benefit
agent in a personal care composition, comprising a cleansing phase;
a high viscosity benefit agent; and a low viscosity benefit agent;
comprising adding the high viscosity benefit agent and the low
viscosity benefit agent separately to the cleansing phase of the
personal care composition.
2. The method of claim 1, wherein the low and high viscosity
benefit agents occupy separate physical domains of the personal
care composition.
3. The method of claim 2, wherein the cleansing phase is structured
and comprises from about 5% to about 20%, by weight of the personal
care composition, of an anionic surfactant; and an amphoteric
surfactant, a zwitterionic surfactant, or a combination
thereof.
4. A method for enhancing deposition of a high viscosity benefit
agent in a personal care composition, comprising a high viscosity
benefit agent and a low viscosity benefit agent comprising,
formulating a personal care composition with a cleansing phase; a
first benefit phase having an average particle size of about 50
.mu.m to about 500 .mu.m and comprising a high viscosity benefit
agent; and a second benefit phase having an average particle size
of about 0.5 .mu.m to about 10 .mu.m and comprising a low viscosity
benefit agent.
5. The method of claim 4, wherein the low and high viscosity
benefit agents occupy separate physical domains of the personal
care composition.
6. The method of claim 5, wherein the cleansing phase is structured
and comprises from about 5% to about 20%, by weight of the personal
care composition, of an anionic surfactant; and an amphoteric
surfactant, a zwitterionic surfactant, or a combination
thereof.
7. The method of claim 6, wherein the cleansing phase is
structured.
8. The method of claim 6, wherein the cleansing phase further
comprises a structuring system comprising from about 0.001% to
about 5%, by weight of the personal care composition, of an
associative polymer; and from about 0.01% to about 5%, by weight of
the personal care composition, of a non-associative polymer.
9. A method for enhancing deposition of a high viscosity benefit
agent in a personal care composition, comprising a cleansing phase,
a high viscosity benefit agent, and a low viscosity benefit agent,
comprising formulating the personal care composition so that the
high viscosity benefit agent and low viscosity benefit agent are in
separate physical domains within the personal care composition.
10. The method of claim 9, wherein the high viscosity benefit agent
and the low viscosity benefit agent are added separately to the
cleansing phase.
11. The method of claim 10, wherein the high viscosity benefit
agent is in a first benefit phase comprising an average particle
size of about 50 .mu.m to about 500 .mu.m; and the low viscosity
benefit agent is in a second benefit phase comprising an average
particle size of about 0.5 .mu.m to about 10 .mu.m.
12. The method of claim 11, wherein the cleansing phase is
structured and comprises: i) from about 5% to about 20%, by weight
of the personal care composition, of an anionic surfactant; ii) an
amphoteric surfactant, a zwitterionic surfactant, or a combination
thereof.
13. The method of claim 12, wherein the personal care composition
comprises from about 0.1% to about 20%, by the weight of the
personal care composition, of the high viscosity benefit agent; and
from about 0.1% to about 20%, by the weight of the personal care
composition, of the low viscosity benefit agent.
14. The method of claim 13, wherein the cleansing phase further
comprises a structuring system comprising from about 0.001% to
about 5%, by weight of the personal care composition, of an
associative polymer and from about 0.01% to about 5.0%, by weight
of the personal care composition, of a non-associative polymer.
15. The method of claim 14, wherein the associative polymer
comprises a polyacrylate, a hydrophobically-modified
polysaccharide, a hydrophobically-modified urethane, or a mixture
thereof.
16. The method of claim 15, wherein the associative polymer
comprises an acrylate/C.sub.10-C.sub.30 alkyl acrylate
cross-polymer.
17. The method of claim 16, wherein the non-associative polymer is
selected from the group consisting of polysaccharides, synthetic
hydrocarbon polymers, and combinations thereof.
18. The method of claim 17, wherein the high viscosity benefit
agent is selected from the group consisting of petrolatum,
microcrystalline wax/mineral oil blends, paraffin wax/mineral oil
blends, wax/oil blends, glyceryl oleate, and combinations
thereof.
19. The method of claim 18, wherein the low viscosity benefit agent
is selected from the group consisting of soy bean oil, sunflower
seed oil, or a combination thereof.
20. The method of claim 19, wherein the first benefit phase is free
of surfactant.
Description
TECHNICAL FIELD
[0001] The present disclosure generally relates to personal care
compositions comprising at least two benefit phases wherein the two
or more benefit phases occupy separate physical domains of the
personal care composition; and methods relating thereto.
BACKGROUND
[0002] Over time, skin cleansing has become part of a personal
hygiene regimen. The cleansing of the skin allows for the removal
of dirt, debris, bacteria, and a myriad of other things that can
cause harm to the skin or the body. Cleansing is often done with
the aid of a surfactant. The surfactant works to help remove
deposited materials from the skin. Unfortunately, surfactants can
also act to remove good things from the skin as well, like lipid.
The lipid on the skin helps, for example, to protect the skin from
losing too much moisture. Removal of too much lipid can leave the
skin vulnerable to becoming dry. One solution for this problem is
to utilize a milder surfactant. Another solution is to replace what
is removed by depositing a benefit material on the skin.
Historically, however, there has been a struggle to effectively
deposit these benefit materials on the skin, especially in rinse
off products like cleansers. As such, there is a need for personal
care compositions that provide enhanced deposition of benefit
materials on the skin.
SUMMARY
[0003] In one example, a method for enhancing deposition of a high
viscosity benefit agent in a personal care composition comprising a
cleansing phase; a high viscosity benefit agent; and a low
viscosity benefit agent; comprising, adding the high viscosity
benefit agent and the low viscosity benefit agent separately to the
cleansing phase of the personal care composition.
[0004] In another example, a method for enhancing deposition of a
high viscosity benefit agent in a personal care composition
comprising a high viscosity benefit agent and a low viscosity
benefit agent comprising, formulating a personal care composition
with a cleansing phase; a first benefit phase having an average
particle size of about 50 .mu.m to about 500 .mu.m and comprising a
high viscosity benefit agent; and a second benefit phase having an
average particle size of about 0.5 .mu.m to about 10 .mu.m and
comprising a low viscosity benefit agent.
[0005] In another example, a method for enhancing deposition of a
high viscosity benefit agent in a personal care composition
comprising a cleansing phase, a high viscosity benefit agent, and a
low viscosity benefit agent, comprising formulating the personal
care composition so that the high viscosity benefit agent and low
viscosity benefit agent are in separate physical domains within the
personal care composition.
[0006] These and other combinations will be better understood from
the more detailed description below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a process diagram for a manufacturing method for
multiphase products.
DETAILED DESCRIPTION
[0008] While the specification concludes with the claims
particularly pointing and distinctly claiming the invention, it is
believed that the present invention will be better understood from
the following description.
[0009] The devices, apparatuses, methods, components, and/or
compositions of the present invention can include, consist
essentially of, or consist of, the components of the present
invention as well as other ingredients described herein. As used
herein, "consisting essentially of" means that the devices,
apparatuses, methods, components, and/or compositions may include
additional ingredients, but only if the additional ingredients do
not materially alter the basic and novel characteristics of the
claimed devices, apparatuses, methods, components, and/or
compositions.
[0010] All percentages and ratios used herein are by weight of the
total composition and all measurements made are at 25.degree. C.,
unless otherwise designated. All measurements used herein are in
metric units unless otherwise specified.
I. DEFINITIONS
[0011] As used herein, the following terms shall have the meaning
specified thereafter:
[0012] "Anhydrous" refers to those compositions, and components
thereof, which are substantially free of water.
[0013] "Associative polymer" refers to a water-dispersible polymer
comprising hydrophobic groups at an end or pendants to a
hydrophilic backbone.
[0014] "High viscosity benefit agent" as used herein refers to a
benefit agent with a viscosity of about 1000 cP or more at
25.degree. C. as defined by the viscosity method under the Method
Section.
[0015] "Low viscosity benefit agent" as used herein refers to a
benefit agent with a viscosity of about 500 cP or less at
25.degree. C. as defined by the viscosity method under the Method
Section.
[0016] "Multiphase" refers to personal care compositions comprising
at least two phases of which can be chemically distinct (e.g., a
structured cleansing phase and a benefit phase). Such phases can be
in direct physical contact with one another. A personal care
composition can be a multiphase personal care composition where
phases of the personal care composition can be blended or mixed to
a significant degree, but still be physically distinct. In these
situations, the physical distinctiveness is undetectable to the
naked eye. The personal care composition can also be a multiphase
personal care composition where phases of the personal care
composition can be made to occupy separate and distinct physical
spaces inside a package where the phases can be stored. In such an
arrangement, the phases can be stored such that they are not in
direct contact with one another (i.e., the phases are not separated
by a barrier and the phases are not emulsified or mixed to any
significant degree). The personal care composition can also be a
multiphase personal care composition where the phases are in
physical contact and are visually distinct. Visually distinct
phases can take many forms (e.g., phases can appear as striped,
marbled). The personal care composition can also include a
combination of one or more of the above multiphase personal care
compositions. In one such arrangement, one blended multiphase
personal care composition can be stacked with another blended
multiphase personal care composition to form a striped
configuration. Additionally, blended multiphase personal care
compositions distinguishable by color can be stacked as stripes
wherein the blended multiphase personal care compositions can be
otherwise similar in average composition.
[0017] "Non-associative polymer" refers to a water-dispersible
polymer with a relatively uniform hydrophilic backbone lacking
hydrophobic groups.
[0018] "Package" refers to any suitable container for a personal
care composition including but not limited to a bottle, tottle,
tube, jar, non-aerosol pump, and combinations thereof.
[0019] "Personal care composition" refers to compositions intended
for topical application to skin or hair. Personal care compositions
can be rinse-off formulations in which the product can be applied
topically to the skin and/or hair and subsequently rinsed from the
skin and/or hair with water. The product could also be wiped off
using a substrate. In either case, it is believed at least a
portion of the product is left behind (i.e., deposited) on the
skin. The personal care compositions can also be used as shaving
aids. The personal care compositions can be extrudable or
dispensable from a package. The personal care compositions can
exhibit a viscosity from about 1,500 cP to about 1,000,000 cP as
measured by a viscosity method as described in the commonly owned
patent application published on Nov. 11, 2004 under U.S.
Publication No. 2004/0223991 A1 entitled, "Multiphase Personal Care
Compositions" filed on May 7, 2004 by Wei, et al. The personal care
compositions can be in the form of, for example, a liquid,
semi-liquid cream, lotion, or gel and are intended for topical
application to the skin and/or hair. Examples of personal care
compositions can include but are not limited to shampoo,
conditioning shampoo, body wash, moisturizing body wash, shower
gels, skin cleansers, cleansing milks, hair and body wash, in
shower body moisturizer, pet shampoo, shaving preparations, and
cleansing compositions used in conjunction with a disposable
cleansing cloth.
[0020] "STnS" refers to sodium trideceth(n) sulfate, wherein n can
define the average number of moles of ethoxylate per molecule.
[0021] "Stable" refers to a personal care composition having a
viscosity change of about 30% or less from an initial viscosity
value after being rapidly aged for 10 days at 50.degree. C.
[0022] "Structured" refers to having a rheology that can confer
stability on the personal care composition. A degree of structure
can be determined by characteristics determined by the Zero Shear
Viscosity Method described below. Accordingly, a structured
cleansing phase of the personal care composition can be considered
to be structured if the structured cleansing phase has a Zero Shear
Viscosity of about 20 Pascal-seconds (Pa-s) or more, about 200 Pa-s
or more, about 500 Pa-s or more, about 1,000 Pa-s or more, about
1,500 Pa-s or more, or about 2,000 Pa-s or more. Other methods for
determining characteristics which can define a degree of structure
are described in U.S. patent application Ser. No. 13/157,665.
[0023] The phrase "substantially free of" as used herein, unless
otherwise specified, means that the personal care composition
comprises less than about 2%, less than about 1%, less than
about0.5%, or even less than about 0.1% of the stated ingredient.
The term "free of", as used herein, means that the personal care
composition comprises 0% of the stated ingredient that is the
ingredient has not been added to the personal care composition.
However, these ingredients may incidentally form as a by-product or
a reaction product of the other components of the personal care
composition.
[0024] "Surfactant component" refers to a total of all anionic,
nonionic, amphoteric, zwitterionic, and cationic surfactants in a
phase. When calculations are based on the surfactant component,
water and electrolytes can be excluded from the calculations
involving the surfactant component since surfactants as
manufactured can be diluted and neutralized.
[0025] "Visually distinct" generally refers to a region of the
multiphase personal care composition having one average
composition, as distinct from another region having a different
average composition, wherein the regions can be visible to the
unaided naked eye. This would not preclude distinct regions from
comprising two similar multiphase personal care compositions or
phases where one multiphase personal care composition or phase can
comprise certain pigments, dyes, particles, and various optional
ingredients, hence providing a region of different average
composition (e.g., different textures or different colors).
II. PERSONAL CARE COMPOSITIONS
[0026] It can be difficult to both cleanse the skin to remove
unwanted things like dirt and deposit beneficial things like
benefit agents in the same process. However, this is exactly the
goal to be accomplished in a personal care composition with benefit
agents. One challenge is to deposit a sufficient amount of skin
benefit agents without compromising the cleansing performance such
as lather and after-use skin feel. Surfactants commonly used in
cleansing compositions tend to diminish the deposition of skin
benefit agents. One way to overcome the deposition challenge is
through the use of highly viscous hydrophobic material such as
petrolatum. But, petrolatum leaves skin greasy/coated which is
undesirable for certain consumers. Alternatively, the low viscosity
natural triglyceride oil is used in body wash to achieve clean skin
feel. But, the low viscosity vegetable oil has poor deposition on
skin with less skin benefits. Therefore, it is very difficult to
achieve high benefit deposition on skin without compromising
performance
[0027] It was previously believed that a low viscosity benefit
agent pre-thickened by a group of specific hydrophobic,
non-anti-foaming polymers, like petrolatum, provides enhanced
deposition of benefit agents in a cleansing composition without
compromising lather performance. However, petrolatum is a
well-known skin moisturizing agent and blending a low viscosity oil
with petrolatum can negatively impact the deposition of petrolatum
as skin benefit agent. For example, when petrolatum, a high
viscosity benefit agent, is pre-blended with a low viscosity
benefit agent, like soy bean oil, the deposition of the petrolatum
is sacrificed, having a deposition of about 70 .mu.g/cm.sup.2.
Conversely, if the soy bean oil and petrolatum are added separately
to the composition as separate benefit phases, the deposition of
the petrolatum is greatly enhanced. A composition made in this
fashion deposited from about 270 .mu.g/cm.sup.2 to about 350
.mu.g/cm.sup.2.
[0028] Without being limited by theory, it is believed that
blending low viscosity and high viscosity benefit agents together
results in a blended benefit phase with a smaller average particle
size of about 10 .mu.m or less, where the benefit agents are in a
single domain. However, when the two benefit agents are added
separately to a cleansing phase, the resulting composition has two
different benefit phases with an average particle size of about 50
.mu.m or more for the high viscosity benefit phase and an average
particle size of about 10 .mu.m or less for the low viscosity
benefit phase and the two benefit phases occupy separate physical
domains. It is believed that the larger particle size benefit
agents tend to deposit better because of larger surface area of
contact of the benefit agent with the skin surface which increases
the adhesion and it becomes harder to remove the lipid particles on
the skin with cleansing surfactant. Thus, maintaining the high
viscosity benefit agent in separate domain helps to maintain its
larger particle size and enhance its deposition. Thus, a personal
care composition with a benefit phase with a particle size of about
50 .mu.m or more are believed to have better deposition onto skin
than those benefit phases with smaller particle sizes.
[0029] A. Structured Cleansing Phase
[0030] As noted herein, a personal care composition can include a
structured cleansing phase and a benefit phase. The structured
cleansing phase and the benefit phase can be in physical contact.
The phases can be blended or mixed to a significant degree, but
still be physically distinct such that the physical distinctiveness
is undetectable to the naked eye. The phases can also be made to
occupy separate and distinct physical spaces inside a package in
which the phases can be stored. In such an arrangement, the
structured cleansing phase and the benefit phase can be stored such
that the phases are not in direct contact with one another. The
structured cleaning phase and the benefit phase can be in physical
contact while remaining visibly distinct to give, for example, a
striped or marbled configuration.
[0031] The personal care composition can include a combination of
one or more of the above multiphase personal care compositions. For
example, one blended multiphase personal care composition can be
stacked as stripes with another blended multiphase personal care
composition.
[0032] The personal care composition can include a cleansing phase.
The cleansing phase can comprise as least one anionic surfactant.
The cleansing phase may contain from 3% to about 20%, from about 5%
to about 15%, from about from about 7% to about 15%, from about 5%
to about 13%, from about 5% to about 20%, or any combination of the
upper, lower, and included limits within the ranges 2% to 30%, of
surfactant, by weight of the personal care composition.
[0033] The cleansing phase may comprise a structured domain. The
structured domain is preferably an opaque structured domain, which
is preferably a lamellar phase. The lamellar phase can provide
resistance to shear, adequate yield to suspend particles and
droplets while providing long term stability because it is
thermodynamically stable. The lamellar phase tends to have a
viscosity that minimizes the need for viscosity modifiers, but they
can be included if desired. The cleaning phase may comprise more
than one surfactant.
[0034] The anionic surfactants can be either linear or branched.
Examples of some suitable linear anionic surfactants include
ammonium laureth sulfate, triethylamine lauryl sulfate,
triethylamine laureth sulfate, triethanolamine lauryl sulfate,
triethanolamine laureth sulfate, monoethanolamine lauryl sulfate,
monoethanolamine laureth sulfate, diethanolamine lauryl sulfate,
diethanolamine laureth sulfate, lauric monoglyceride sodium
sulfate, sodium laureth sulfate, potassium laureth sulfate, sodium
lauryl sarcosinate, sodium lauroyl sarcosinate, lauryl sarcosine,
cocoyl sarcosine, ammonium cocoyl sulfate, sodium cocoyl
isethionate, ammonium lauroyl sulfate, sodium cocoyl sulfate,
sodium lauroyl sulfate, potassium cocoyl sulfate, potassium lauryl
sulfate, monoethanolamine cocoyl sulfate, sodium tridecyl benzene
sulfonate, sodium dodecyl benzene sulfonate, and combinations
thereof.
[0035] Examples of some suitable branched anionic surfactants
include but are not limited to the following surfactants: sodium
trideceth sulfate, sodium tridecyl sulfate, sodium C.sub.12-13
alkyl sulfate, sodium C.sub.12-15 alkyl sulfate, sodium C.sub.11-15
alkyl sulfate, sodium C.sub.12-18 alkyl sulfate, sodium C.sub.10-16
alkyl sulfate, sodium C.sub.12-13 pareth sulfate, sodium
C.sub.12-13 pareth-n sulfate, sodium C.sub.12-14 pareth-n sulfate,
and combinations thereof. Other salts of all the aforementioned
surfactants are useful, such as TEA, DEA, ammonia, potassium salts.
Useful alkoxylates include the ethylene oxide, propylene oxide and
EO/PO mixed alkoxylates. Phosphates, carboxylates and sulfonates
prepared from branched alcohols are also useful anionic branched
surfactants. Branched surfactants can be derived from synthetic
alcohols such as the primary alcohols from the liquid hydrocarbons
produced by Fischer-Tropsch condensed syngas, for example Safol.TM.
23 Alcohol available from Sasol North America, Houston, Tex.; from
synthetic alcohols such as Neodol.TM. 23 Alcohol available from
Shell Chemicals, USA; from synthetically made alcohols such as
those described in U.S. Pat. No. 6,335,312 issued to Coffindaffer,
et al on Jan. 1, 2002. Suitable examples of alcohols are Safol.TM.
23 and Neodol.TM. 23. Suitable examples of alkoxylated alcohols are
Safol.TM. 23-3 and Neodol.TM. 23-3. Sulfates can be prepared by
conventional processes to high purity from a sulfur based SO.sub.3
air stream process, chlorosulfonic acid process, sulfuric acid
process, or Oleum process. Preparation via SO.sub.3 air stream in a
falling film reactor is a preferred sulfation process.
[0036] The anionic surfactant may also be STnS, wherein n can
define average moles of ethoxylation. A structured cleansing phase
can include from about 5% to about 20%, from about 7% to about 18%,
from about 9% to about 16%, from about 11% to about 14%, by weight
of the personal care composition, of STnS. A structured cleansing
phase can include from 5% to 20%, from 7% to 18%, from 9% to 16%,
from 11% to 14%, by weight of the personal care composition, of
STnS. n can range from about 0 to about 3, from about 0.5 to about
2.7, from about 1.1 to about 2.5, from about 1.8 to about 2.2, or n
can be about 2. When n is less than 3, STnS can provide improved
stability, improved compatibility of benefit agents within the
personal care compositions, and increased mildness of the personal
care composition. Such described benefits of STnS are disclosed in
U.S. patent application Ser. No. 13/157,665.
[0037] Further, the structured cleansing phase can comprise a
structuring system wherein the structuring system can comprise an
associative polymer and a non-associative polymer. The structuring
system can comprise from about 0.01% to about 5%, from about 0.05%
to about 1%, from about 0.07% to about 0.5%, or from about 0.1% to
about 0.3%, by weight of the personal care composition, of a
non-associative polymer. The structuring system can also comprise
from 0.01% to 5%, from 0.05% to 1%, from 0.07% to 0.5%, or from
0.1% to 0.3%, by weight of the personal care composition, of a
non-associative polymer. The structuring system can comprise from
about 0.001% to about 5%, from about 0.005% to about 0.5%, from
about 0.007% to about 0.05%, from about 0.008% to about 0.04%, or
from about 0.01% to about 0.03%, by weight of the personal care
composition, of an associative polymer. The structuring system can
comprise from 0.001% to 5%, from 0.005% to 0.5%, from 0.007% to
0.05%, from 0.008% to 0.04%, or from 0.01% to 0.03%, by weight of
the personal care composition, of an associative polymer.
[0038] Such associative polymers can be crosslinked, alkali
swellable, associative polymers comprising acidic monomers and
associative monomers with hydrophobic end groups, whereby the
associative polymer comprises a percentage hydrophobic modification
and a hydrophobic side chain comprising alkyl functional groups.
Without intending to be limited by theory, it is believed the
acidic monomers can contribute to an ability of the associative
polymer to swell in water upon neutralization of acidic groups; and
associative monomers anchor the associative polymer into structured
surfactant hydrophobic domains, e.g., lamellae, to confer structure
to the surfactant phase and keep the associative polymer from
collapsing and losing effectiveness in the presence of an
electrolyte. The crosslinked, associative polymer can comprise a
percentage hydrophobic modification, which is a mole percentage of
monomers expressed as a percentage of a total number of all
monomers in a polymer backbone, including both acidic and other
non-acidic monomers. Percentage hydrophobic modification of the
associative polymer, hereafter % HM, can be determined by the ratio
of monomers added during synthesis or by analytical techniques such
as proton nuclear magnetic resonance (NMR). Associative alkyl side
chains can comprise, for example, butyl, propyl, stearyl, steareth,
cetyl, lauryl, laureth, octyl, behenyl, beheneth, steareth, or
other linear, branched, saturated, or unsaturated alkyl or alketh
hydrocarbon side chains.
[0039] It has also been discovered that crosslinked, associative
polymers having certain % HM and certain carbon numbers of
hydrophobic end groups of alkyl side chains can provide significant
enhancement of structure to personal care compositions comprising a
structured surfactant, especially to personal care compositions
comprising reduced levels of surfactant. Such associative polymers
can also provide the above structure at surprisingly low levels of
polymer structurant. Concentrations of associative polymers of up
to about 5% or even 10% have been known to provide a sufficient
amount structure (e.g., exemplary compositions of U.S. Pat. No.
7,119,059 (Librizzi, et al.) and U.S. Pat. No. 6,897,253
(Schmucker-Castner, et al.). It has been discovered that when an
associative polymer % HM and an alkyl side chain number of carbons
can be optimized, the structure of an aqueous structured surfactant
phase can be increased using only less than about 3 wt %, less than
about 2%, less than about 1%, and less than about 0.2%, of an
associative polymer, as a percentage of an aqueous structured
surfactant phase.
[0040] The acidic monomer can comprise any acid functional group,
for example sulfate, sulfonate, carboxylate, phosphonate, or
phosphate or mixtures of acid groups. The acidic monomer can
comprise, for example, a carboxylate. Alternatively, the acidic
monomer can be an acrylate, including acrylic acid and/or
methacrylic acid. The acidic monomer can comprise a polymerizable
structure, e.g., vinyl functionality. Mixtures of acidic monomers,
for example acrylic acid and methacrylic acid monomer mixtures, may
be useful as well.
[0041] The associative monomer can comprise a hydrophobic end group
and a polymerizable component, e.g., vinyl, which can be attached.
The hydrophobic end group can be attached to the polymerizable
component, hence to the polymer chain, by different means but can
be attached by an ether or ester or amide functionality, such as an
alkyl acrylate or a vinyl alkanoate monomer. The hydrophobic end
group can also be separated from the chain, for example, by an
alkoxy ligand such as an alkyl ether. The associative monomer can
be, for example, an alkyl ester, an alkyl (meth)acrylate, where
(meth)acrylate is understood to mean either methyl acrylate or
acrylate, or mixtures of the two.
[0042] Sometimes, the hydrophobic end group of the associative
polymer can be incompatible with the aqueous phase of the personal
care composition and can associate with lathering surfactant
hydrophobe components. Without intending to be limited by theory,
it is believed that longer alkyl chains of structuring polymer
hydrophobe end groups can increase incompatibility with the aqueous
phase to enhance structure, whereas shorter alkyl chains having
carbon numbers closely resembling lathering surfactant hydrophobes
(e.g., 12 to 14 carbons) or multiples thereof (for bilayers, e.g.)
can also be effective. An ideal range of hydrophobic end group
carbon numbers combined with an optimal percentage of hydrophobic
monomers expressed as a percentage of the polymer backbone can
provide increased structure to the personal care composition
comprising a structured surfactant with low levels of polymer
structurant.
[0043] An exemplary associative polymer can include AQUPEC.RTM.
SER-300 made by Sumitomo Seika of Japan, which is an
acrylate/C.sub.10-C.sub.30 alkyl acrylate cross-polymer and
comprises stearyl side chains with less than about 1% HM.
Associative polymers can comprise about C.sub.16 (cetyl) alkyl
hydrophobic side chains with about 0.7% hydrophobic modification,
but a percentage hydrophobic modification can be up to an aqueous
solubility limit in surfactant compositions (e.g., up to 2%, 5%, or
10%). Other associative polymers can include stearyl, octyl, decyl
and lauryl side chains, alkyl acrylate polymers, polyacrylates,
hydrophobically-modified polysaccharides, hydrophobically-modified
urethanes, AQUPEC.RTM. SER-150 (acrylate/C.sub.10-C.sub.30 alkyl
acrylate cross-polymer) comprising about C.sub.18 (stearyl) side
chains and about 0.4% HM, and AQUPEC.RTM. HV-701EDR which comprises
about C.sub.8 (octyl) side chains and about 3.5% HM, and mixtures
thereof. Another exemplary associative polymer can be Stabylen 30
manufactured by 3V Sigma S.p.A., which has branched isodecanoate
hydrophobic associative side chains.
[0044] As set forth above, the structured cleansing phase of a
personal care composition can further include a non-associative
polymer. Suitable non-associative polymers can include
water-dispersible polymers with relatively uniform hydrophilic
backbone lacking hydrophobic groups. Examples of non-associative
polymers can include biopolymer polysaccharides (e.g., xanthan gum,
gellan gum), cellulosic polysaccharides (e.g., carboxymethyl
cellulose, carboxymethyl hydroxyethyl cellulose), other
polysaccharides (e.g., guar gum, hydroxypropyl guar, and sodium
alginate), and synthetic hydrocarbon polymers (e.g., polyacrylamide
and copolymers, polyethylene oxide, polyacrylic acid
copolymers).
[0045] Personal care compositions can additionally comprise an
organic cationic deposition polymer in one or more phases as a
deposition aid for the benefit agents described herein. Suitable
cationic deposition polymers can contain cationic
nitrogen-containing moieties such as quaternary moieties.
Non-limiting examples of cationic deposition polymers can include
polysaccharide polymers, such as cationic cellulose derivatives.
Cationic cellulose polymers can be salts of hydroxyethyl cellulose
reacted with trimethyl ammonium substituted epoxide, referred to in
the industry (CTFA) as Polyquaternium 10, which can be available
from Amerchol Corp. (Edison, N.J.) in their Polymer KG, JR, and LR
series of polymers. Other suitable cationic deposition polymers can
include cationic guar gum derivatives, such as guar
hydroxypropyltrimonium chloride, specific examples of which can
include the Jaguar series commercially available from Rhodia Inc.
and N-Hance polymer series commercially available from Aqualon.
Deposition polymers can have a cationic charge density from about
0.8 meq/g to about 2.0 meq/g or from about 1.0 meq/g to about 1.5
meq/g, or about 0.96 meq/g.
[0046] The personal care composition can be optionally free of or
substantially free of sodium lauryl sulfate, hereinafter SLS,
and/or ammonium lauryl sulfate, hereinafter ALS, and can comprise
at least a 70% lamellar structure. However, in an alternative
arrangement, the structured cleansing phase can comprise at least
one surfactant, wherein the at least one surfactant includes SLS
and/or ALS. Suitable examples of SLS are described in U.S. patent
application Ser. No. 12/817,786.
[0047] A personal care composition can further comprise from about
0.1% to about 20%, by weight of the personal care composition, of a
cosurfactant. The cosurfactant can comprise amphoteric surfactants,
zwitterionic surfactants, or mixtures thereof. For example, a
personal care composition can include an amphoteric surfactant
and/or a zwitterionic surfactant. Suitable amphoteric or
zwitterionic surfactants can include those described in U.S. Pat.
Nos. 5,104,646 and 5,106,609.
[0048] Amphoteric surfactants can include those that can be broadly
described as derivatives of aliphatic secondary and tertiary amines
in which an aliphatic radical can be a straight or branched chain
and wherein an aliphatic substituent can contain from about 8 to
about 18 carbon atoms such that one carbon atom can contain an
anionic water solubilizing group, e.g., carboxy, sulfonate,
sulfate, phosphate, or phosphonate. Examples of compounds falling
within this definition can be sodium 3-dodecyl-aminopropionate,
sodium 3-dodecylaminopropane sulfonate, sodium lauryl sarcosinate,
N-alkyltaurines such as the one prepared by reacting dodecylamine
with sodium isethionate according to the teaching of U.S. Pat. No.
2,658,072, N-higher alkyl aspartic acids such as those produced
according to the teaching of U.S. Pat. No. 2,438,091, and products
described in U.S. Pat. No. 2,528,378. Other examples of amphoteric
surfactants can include sodium lauroamphoacetate, sodium
cocoamphoactetate, disodium lauroamphoacetate disodium
cocodiamphoacetate, and mixtures thereof. Amphoacetates and
diamphoacetates can also be used.
[0049] Zwitterionic surfactants suitable for use can include those
that are broadly described as derivatives of aliphatic quaternary
ammonium, phosphonium, and sulfonium compounds, in which aliphatic
radicals can be straight or branched chains, and wherein an
aliphatic substituent can contain from about 8 to about 18 carbon
atoms such that one carbon atom can contain an anionic group, e.g.,
carboxy, sulfonate, sulfate, phosphate, or phosphonate. Other
zwitterionic surfactants can include betaines, including
cocoamidopropyl betaine.
[0050] Other suitable surfactants or cosurfactants that can
generally be used in a structured cleansing phase for a personal
care composition are described in McCutcheon's: Detergents and
Emulsifiers North American Edition (Allured Publishing Corporation
1947) (1986), McCutcheon's, Functional Materials North American
Edition (Allured Publishing Corporation 1973) (1992) and U.S. Pat.
No. 3,929,678 (filed Aug. 1, 1974).
[0051] The structured cleansing phase of the personal care
composition can also comprise water. The structured cleansing phase
of the personal care composition can comprise from about 10% to
about 90%, from about 40% to about 85%, or from about 60% to about
80%, by weight of the personal care composition, of water.
[0052] Other optional additives can be included in the cleaning
phase, including, for example, an emulsifier (e.g., non-ionic
emulsifier) and electrolyes. Suitable electrolytes can include
anions such as phosphate, chloride, sulfate, citrate, and mixtures
thereof and cations such as sodium, ammonium, potassium, magnesium,
and mixtures thereof. For example, suitable electrolytes can
include sodium chloride, ammonium chloride, sodium sulfate,
ammonium sulfate, and mixtures thereof. Other suitable emulsifiers
and electrolytes are described in U.S. patent application Ser. No.
13/157,665.
[0053] B. Benefit Phase
[0054] As noted herein, personal care compositions can include two
or more benefit phases. The benefit phases can be hydrophobic
and/or anhydrous. The benefit phases can also be substantially free
of or free of surfactant.
[0055] The First Benefit Phase
[0056] The first benefit phase can comprise from about 0.1% to
about 20%, by weight of the personal care composition, of a high
viscosity skin benefit agent. The first benefit phase comprising a
high viscosity benefit agent can have an average particle size of
at least about 50 .mu.m, at least about 100 .mu.m, at least 200
.mu.m, at least about 300 .mu.m, to about 10,000 .mu.m.
[0057] High viscosity benefit agents can include water insoluble or
hydrophobic benefit agents. Examples of high viscosity benefit
agents can include petrolatum, microcrystalline wax/mineral oil
blends, paraffin wax/mineral oil blend, lanolin, lanolin
derivatives, wax/mineral oil blends, triglyceride waxes, synthetic
triglycerides, and combinations thereof. Other suitable high
viscosity benefit agents are described in U.S. patent application
Ser. No. 13/157,665.
[0058] High viscosity benefit agents can have a viscosity of about
1,000 cP or more at 25.degree. C. In one example, the viscosity of
the high viscosity benefit agent is greater than about 10,000 cP at
25.degree. C. In another example, the high viscosity benefit agent
has a viscosity of about 100,000 cP at 25.degree. C. The viscosity
of the high viscosity benefit agent can be up to about 1,000,000 cP
at 25.degree. C.
[0059] The Second Benefit Phase
[0060] A personal care composition can comprise a second benefit
phase. A second benefit phase can comprise a low viscosity benefit
agent. A low viscosity benefit agent has a viscosity of less than
about 500 cP at 25.degree. C. In one example, the low viscosity
benefit agent has a viscosity of less than 100 cP at 25.degree.
C.
[0061] An example of a low viscosity benefit agent includes
glycerides. Non-limiting examples of low viscosity glycerides
suitable for use as low viscosity hydrophobic benefit agents herein
can include soybean oil, sun flower seed oil, castor oil, safflower
oil, corn oil, walnut oil, peanut oil, olive oil, cod liver oil,
almond oil, avocado oil, palm oil, sesame oil, vegetable oils,
vegetable oil derivatives, coconut oil and derivatized coconut oil,
cottonseed oil and derivatized cottonseed oil, jojoba oil, and
combinations thereof.
[0062] Another example of a low viscosity benefit agent is
SEFOSE.RTM. which includes one or more types of sucrose polyesters.
Sucrose polyesters are derived from a natural resource and
therefore, the use of sucrose polyesters as the benefit agent can
result in a positive environmental impact. Sucrose polyesters are
polyester materials having multiple substitution positions around
the sucrose backbone coupled with the chain length, saturation, and
derivation variables of the fatty chains. Such sucrose polyesters
can have an esterification ("IBAR") of greater than about 5. For
example, the sucrose polyester may have an IBAR of about 5 to about
8. In another example, the sucrose polyester may have an IBAR of
about 5-7; in another example, the sucrose polyester can have an
IBAR of about 6. In yet another example, the sucrose polyester can
have an IBAR of about 8. As sucrose polyesters can be derived from
natural resources, a distribution in the IBAR and chain length may
exist. For example, a sucrose polyester having an IBAR of 6 may
contain a mixture of mostly IBAR of about 6, with some IBAR of
about 5, and some IBAR of about 7. Additionally, such sucrose
polyesters may have a saturation or iodine value ("IV") of about 3
to about 140. In another example, the sucrose polyester may have an
IV of about 10 to about 120. In yet another example, the sucrose
polyester may have an IV of about 20 to 100. Further, such sucrose
polyesters may have a chain length of about C.sub.12 to
C.sub.20.
[0063] Non-limiting examples of alkyl esters suitable for use as
low viscosity hydrophobic benefit agents herein can include
isopropyl esters of fatty acids and long chain esters of long chain
(i.e. C.sub.10-C.sub.24) fatty acids, e.g., cetyl ricinoleate,
non-limiting examples of which can include isopropyl palmitate,
isopropyl myristate, cetyl riconoleate, and stearyl riconoleate.
Other examples can include hexyl laurate, isohexyl laurate,
myristyl myristate, isohexyl palmitate, decyl oleate, isodecyl
oleate, hexadecyl stearate, decyl stearate, isopropyl isostearate,
diisopropyl adipate, diisohexyl adipate, dihexyldecyl adipate,
diisopropyl sebacate, acyl isononanoate lauryl lactate, myristyl
lactate, cetyl lactate, and combinations thereof.
[0064] Non-limiting examples of silicone oils suitable for use as
low viscosity hydrophobic benefit agents herein can include
dimethicone copolyol, dimethylpolysiloxane, diethylpolysiloxane,
mixed C.sub.1-C.sub.30 alkyl polysiloxanes, phenyl dimethicone,
dimethiconol, and combinations thereof. Non-limiting examples of
silicone oils useful herein are described in U.S. Pat. No.
5,011,681. Still other suitable low viscosity hydrophobic skin
benefit agents can include milk triglycerides (e.g., hydroxylated
milk glyceride) and polyol fatty acid polyesters.
[0065] C. Other Optional Materials
[0066] Additional optional materials can also be added to the
personal care composition to treat the skin, or to modify the
aesthetics of the personal care composition as is the case with
perfumes, colorants, dyes, or the like. Optional materials useful
in products herein can be categorized or described by their
cosmetic and/or therapeutic benefit or their postulated mode of
action or function. However, it can be understood that actives and
other materials useful herein can, in some instances, provide more
than one cosmetic and/or therapeutic benefit or function or operate
via more than one mode of action. Therefore, classifications herein
can be made for convenience and cannot be intended to limit a
material to a particularly stated application or applications
listed. A precise nature of these optional material and levels of
incorporation thereof, will depend on the physical form of the
personal care composition and the nature of the cleansing operation
for which it is to be used. Optional materials can usually be
formulated at about 6% or less, about 5% or less, about 4% or less,
about 3% or less, about 2% or less, about 1% or less, about 0.5% or
less, about 0.25% or less, about 0.1% or less, about 0.01% or less,
or about 0.005% or less by weight of the personal care
composition.
[0067] The personal care composition can also comprise a benefit
component that can be selected from the group consisting of
thickening agents; preservatives; antimicrobials; fragrances;
chelators (e.g., such as those described in U.S. Pat. No. 5,487,884
issued to Bisset, et al.); sequestrants; vitamins (e.g., Retinol);
vitamin derivatives (e.g., tocophenyl actetate, niacinamide,
panthenol); sunscreens; desquamation actives (e.g., such as those
described in U.S. Pat. Nos. 5,681,852 and 5,652,228 issued to
Bisset); anti-wrinkle/anti-atrophy actives (e.g., N-acetyl
derivatives, thiols, hydroxyl acids, phenol); anti-oxidants (e.g.,
ascorbic acid derivatives, tocophenol) skin soothing agents/skin
healing agents (e.g., panthenoic acid derivatives, aloe vera,
allantoin); skin lightening agents (e.g., kojic acid, arbutin,
ascorbic acid derivatives) skin tanning agents (e.g.,
dihydroxyacteone); anti-acne medicaments; essential oils; sensates;
pigments; colorants; pearlescent agents; interference pigments
(e.g., such as those disclosed in U.S. Pat. No. 6,395,691 issued to
Liang Sheng Tsaur, U.S. Pat. No. 6,645,511 issued to Aronson, et
al., U.S. Pat. No. 6,759,376 issued to Zhang, et al, U.S. Pat. No.
6,780,826 issued to Zhang, et al.) particles (e.g., talc, kolin,
mica, smectite clay, cellulose powder, polysiloxane, silicas,
carbonates, titanium dioxide, polyethylene beads) hydrophobically
modified non-platelet particles (e.g., hydrophobically modified
titanium dioxide and other materials described in a commonly owned,
patent application published on Aug. 17, 2006 under Publication No.
2006/0182699A, entitled "Personal Care Compositions Containing
Hydrophobically Modified Non-platelet particle filed on Feb. 15,
2005 by Taylor, et al.) and mixtures thereof. The personal care
compositions can comprise from about 0.1% to about 4%, by weight of
the personal care composition, of hydrophobically modified titanium
dioxide. Other such suitable examples of such skin actives are
described in U.S. patent application Ser. No. 13/157,665.
[0068] Other optional materials can be those materials approved for
use in cosmetics and that are described in the CTFA Cosmetic
Ingredient Handbook, Second Edition, The Cosmetic, Toiletries, and
Fragrance Association, Inc. 1988, 1992.
III. METHOD OF MANUFACTURING
[0069] The personal care compositions as described herein can be
manufactured by a multi-benefit stream method. In this method, the
components of the cleansing phase are added in a tank with simple
mixing to blend the components together. A benefit phase comprising
a high viscosity benefit agent is placed into a separate tank and
heated to between 50.degree. C. to 80.degree. C. (or above its
melting point, whichever is greater). An additional benefit phase
comprising a low viscosity benefit agent is placed into a second
tank and heated to 20.degree. C.-60.degree. C. (or above its
melting point, whichever is greater). Once the components of the
cleansing phase are mixed, one of the benefit phases is added to
the cleansing phase by injecting the benefit phase into a mixing
device such as a static mixer, rotor-stator device, recirculation
loop, or into a mixing zone in a mix tank, with the cleansing
phase. The remaining benefit phase is then added to the composition
in a fashion similar to that of the first benefit phase. This
differs from traditional manufacturing where the benefit agents are
combined in a single tank, heated, and added to the surfactant
phase by simple mixing. The benefit of adding two lipid streams via
two different injection points is the creation of two separate
particle size domains.
IV. OTHER METHODS
[0070] In addition to the compositions above, inventive methods are
also present. In one example, a method for enhancing deposition of
a high viscosity benefit agent in a personal care composition
comprising a cleansing phase; a high viscosity benefit agent; and a
low viscosity benefit agent; comprising, adding the high viscosity
benefit agent and the low viscosity benefit agent separately to the
cleansing phase of the personal care composition.
[0071] In another example, a method for enhancing deposition of a
high viscosity benefit agent in a personal care composition
comprising a high viscosity benefit agent and a low viscosity
benefit agent comprising, formulating a personal care composition
with a cleansing phase; a first benefit phase having an average
particle size of about 50 .mu.m to about 500 .mu.m and comprising a
high viscosity benefit agent; and a second benefit phase having an
average particle size of about 0.5 .mu.m to about 10 .mu.m and
comprising a low viscosity benefit agent.
[0072] In another example, a method for enhancing deposition of a
high viscosity benefit agent in a personal care composition
comprising a cleansing phase, a high viscosity benefit agent, and a
low viscosity benefit agent, comprising formulating the personal
care composition so that the high viscosity benefit agent and low
viscosity benefit agent are in separate physical domains within the
personal care composition.
[0073] For simplicity, only a minimal amount of compositional
ingredients and variants are discussed here. The above disclosure
relating to the compositions and ingredients are equally applicable
here as well.
V. Test Methods
[0074] A. T-Bar Viscosity Method
[0075] The viscosity of a personal care composition can be assessed
by the T-Bar Viscosity Method. The apparatus for T-Bar measurements
includes a Brookfield DV-II+ Pro Viscometer with Helipath
Accessory; a chuck, weight and closer assembly for T-bar
attachment; a T-bar Spindle D, a personal computer with Rheocalc
software from Brookfield, and a cable connecting a Brookfield
Viscometer to a computer. First, weigh 80 grams of a personal care
composition in a 4-oz. glass jar. Measure a T-bar viscosity by
carefully dropping the T-Bar Spindle to an interior bottom of the
glass jar and set the Helipath stand to travel in an upward
direction. Open the Rheocalc software and set the following data
acquisition parameters: Speed to 5 rpm, Time Wait for Torque to
00:01 (1 second), and Loop Start Count to 100. Start data
acquisition and turn on the Helipath stand to travel upward at a
speed of 22 mm/minute. The T-Bar viscosity is an average T-Bar
viscosity reading between the 10.sup.th reading and the 90.sup.th
reading (the first ten readings and the last ten readings are not
used for the average T-Bar viscosity calculation). The T-Bar
viscosity reading is provided in cP. After obtaining the initial
viscosity reading, place the personal care composition at
50.degree. C. for 10 days for rapid aging. After finishing the
stability testing at 50.degree. C., the sample is equilibrated at
25.degree. C. for 24 hours. Then repeat viscosity measurement to
obtain final viscosity. Measure percent change of the initial
viscosity from the final viscosity measurement to obtain the
percent change in viscosity.
[0076] B. Zero Shear Viscosity and Young's Modulus Methods
[0077] The Zero Shear Viscosity of a material which is a phase or a
component of the personal care composition, can be measured either
prior to combining in the personal care composition, after
preparing a composition, or first separating a phase or component
from a personal care composition by suitable physical separation
means, such as centrifugation, pipetting, cutting away
mechanically, rinsing, filtering, or other separation means.
[0078] A controlled stress rheometer such as a TA Instruments
AR2000 Rheometer is used to determine the Zero Shear Viscosity. The
determination is performed at 25.degree. C. with a 4 cm diameter
parallel plate measuring system and a 1 mm gap. The geometry has a
shear stress factor of 79580 m-3 to convert torque obtained to
stress. Serrated plates can be used to obtain consistent results
when slip occurs.
[0079] First, material is positioned on a rheometer base plate; the
measurement geometry (upper plate) is moved into position 1.1 mm
above the base plate. Excess material at the geometry edge is
removed by scraping after locking the geometry. The geometry is
then moved to the target 1 mm position above the base plate and a
pause of about 2 minutes is allowed to allow loading stresses to
relax. This loading procedure ensures no tangential stresses are
loaded at the measurement onset which can influence the results
obtained. If the material comprises particles discernible to the
eye or by feel (e.g., beads) that are larger than about 150 microns
in number average diameter, the gap setting between the base plate
and upper plate is increased to the smaller of 4 mm or 8-fold the
diameter of the 95.sup.th volume percentile particle diameter. If a
phase has any particle larger than 5 mm in any dimension, the
particles are removed prior to the measurement.
[0080] The measurement is performed by applying a continuous shear
stress ramp from 0.1 Pa to 1,000 Pa over a time interval of 4
minutes using a logarithmic progression, i.e., measurement points
evenly spaced on a logarithmic scale. Thirty measurement points per
decade of stress increase are obtained. If the measurement result
is incomplete, for example, if material is observed to flow from
the gap, results obtained are evaluated with incomplete data points
excluded. If there are insufficient points to obtain an accurate
measurement, the measurement is repeated with increased number of
sample points.
[0081] The Young's Modulus (Pa) is obtained by graphing Stress (Pa)
vs. Strain (unitless) and obtaining a slope of a regression line of
an initial linear region between Stress vs. Strain, typically
occurring in the region below about 4% strain. If the relationship
is not linear, the linear regression line slope below 2% strain is
taken as the Young's Modulus (Pa), using unitless strain.
[0082] The Zero Shear Viscosity is obtained by taking a first
median value of viscosity in Pascal-seconds (Pa-s) for viscosity
data obtained between and including 0.1 Pa and a point where
viscosity begins to steeply decline. After taking the first median
viscosity, all viscosity values greater than 5-fold the first
median value and less than 0.2 x the median value are excluded, and
a second median viscosity value is obtained of the same viscosity
data, excluding the indicated data points. The second median
viscosity so obtained is the Zero Shear Viscosity.
[0083] As set forth above, a structured cleansing phase can be
considered to be structured if the structured cleansing phase has a
Zero Shear Viscosity of about 200 Pa-s or more, about 500 Pa-s or
more, about 1,000 Pa-s or more, about 1,500 Pa-s or more, or about
2,000 Pa-s or more.
[0084] C. Benefit Agent Viscosity Method A controlled stress
rheometer such as a TA Instruments AR2000 Rheometer is used to
determine the Viscosity of benefit agent. The determination is
performed at 25.degree. C. with a 4 cm diameter parallel plate
measuring system and a 1 mm gap. The geometry has a shear stress
factor of 79580 m-3 to convert torque obtained to stress. Serrated
plates can be used to obtain consistent results when slip
occurs.
[0085] First, the benefit material is positioned on a rheometer
base plate; the measurement geometry (upper plate) is moved into
position 1.1 mm above the base plate. Excess material at the
geometry edge is removed by scraping after locking the geometry.
The geometry is then moved to the target 1 mm position above the
base plate and a pause of about 2 minutes is allowed to allow
loading stresses to relax. This loading procedure ensures no
tangential stresses are loaded at the measurement onset which can
influence the results obtained. If the material comprises particles
discernible to the eye or by feel (e.g., beads) that are larger
than about 150 microns in number average diameter, the gap setting
between the base plate and upper plate is increased to the smaller
of 4 mm or 8-fold the diameter of the 95.sup.th volume percentile
particle diameter. If a phase has any particle larger than 5 mm in
any dimension, the particles are removed prior to the
measurement.
[0086] The measurement is performed by applying a continuous shear
stress ramp from 0.1 Pa to 1,000 Pa over a time interval of 4
minutes using a logarithmic progression, i.e., measurement points
evenly spaced on a logarithmic scale. Thirty measurement points per
decade of stress increase are obtained. If the measurement result
is incomplete, for example, if material is observed to flow from
the gap, results obtained are evaluated with incomplete data points
excluded. If there are insufficient points to obtain an accurate
measurement, the measurement is repeated with increased number of
sample points.
[0087] The Viscosity of the benefit agent is obtained by graphing
Viscosity (Pa.S) vs. Shear Rate (/s) and obtaining consistency
value (K) and shear index (n) through a power law fit. The
consistency value (K) is defined as the benefit phase/agent
viscosity.
[0088] D. Third-Phase Method for Determining Structured Surfactant
Stability
[0089] A Third-Phase Method can be used to determine structured
surfactant phase stability in a personal care composition. The
method involves placing the personal care compositions at
50.degree. C. for 10 days for rapid aging. After rapid aging,
transfer about 4 grams of the personal care composition into a
Beckman Centrifuge Tube (11 mm.times.60 mm). Place the centrifuge
tube in a Beckman LE-80 Ultracentrifuge and operate the
ultracentrifuge under the following conditions: 50,000 rpm, 2
hours, and 40.degree. C.
[0090] After ultracentrifugation, determine the third-phase volume
by measuring a height for each of various surfactant phases using
an Electronic Digital Caliper (within 0.01 mm).
[0091] A very top layer is a hydrophobic benefit phase layer (e.g.,
hydrocarbons or soybean oil). The layers below the hydrophobic
benefit phase layers containing surfactant/water can determined by
the following: Ha is a height of all layers containing
surfactant/water and Hb is a height of a clear "third-phase" layer
just below the hydrophobic benefit phase layer. It is important to
record the readings within 30 minutes after the ultracentrifugation
is finished to minimize material migration across different layers.
The third phase volume is calculated as: Third-Phase Volume
%=Hb/Ha*100%.
[0092] A personal care composition comprising a structured
surfactant can comprises less than about 10% "third-phase" volume,
less than about 5% "third-phase" volume, less than about 2%
"third-phase" volume, or less than about 1% "third-phase" volume
after rapid aging stability protocol. In another arrangement, the
personal care composition comprising a structured surfactant can
comprise about 0% "third-phase" volume after rapid aging
protocol.
[0093] E. Ultracentrifugation Method
[0094] The Ultracentrifugation Method is a physical method used to
determine an amount of structure in a personal care composition or
a subset of a personal care composition. The method can also be
used to determine a rate at which a personal care composition
comprising a structured surfactant dissolves upon dilution to
present effective amounts of surfactant to a cleaning environment
proximal to surfaces.
[0095] A personal care composition can be separated by
ultracentrifuge into separate but distinguishable layers. The
personal care composition can have multiple distinguishable layers
(e.g., a structured surfactant layer and a benefit layer).
[0096] First, dispense about 4 grams of the personal care
composition into a Beckman Centrifuge Tube (11 mm.times.60 mm) to
fill the tube. Next, dilute the personal care composition to a 10%
Dilution Level using 90% of the personal care composition and 10%
DI water using an appropriate mixer and dispense an equal amount of
the personal care composition into a companion centrifuge tube.
Continue to dilute the personal care composition and fill tubes in
the same manner until a 60% Dilution Level is obtained for the
personal care composition using 40% of the personal care
composition with 60% DI water. Place the centrifuge tubes in an
ultracentrifuge (Beckman Model L8-M or equivalent) using a sling
rotor and ultracentrifuge using the following conditions: 50,000
rpm, 2 hours, and 40.degree. C.
[0097] Measure relative phase volumes for each phase of the
personal care composition by measuring a height for each layer
using an Electronic Digital Caliper (within 0.01mm). Layers are
identified by those skilled in the art by physical observation
techniques paired with chemical identification if needed. For
example, the structured surfactant layer can be identified by
transmission electron microscopically (TEM), polarized light
microscopy, and/or X-ray diffraction as a structured lamellar phase
comprising multilamellar vesicles, and the hydrophobic benefit
layer can be identified by its low moisture content (less than
about 10% water as measured by Karl Fischer Titration). Measure a
total height Ha, which includes all materials in the
ultracentrifuge tube. Next, the height of each layer is measured
from a bottom of the centrifuge tube to a top of the layer, and the
span of each layer can be algebraically determined by subtraction.
The benefit layer may comprise several layers. If the benefit phase
splits, a sum of the benefit layers measured is the benefit layer
height, Hb. Generally, a hydrophobic benefit layer, when present,
is at a top of the centrifuge tube.
[0098] The surfactant phase may comprise several layers or a single
layer, Hc. There may also be a micellar, unstructured, clear
isotropic layer at the bottom or next to the bottom of the
ultracentrifuge tube. Layers immediately above the isotropic phase
generally comprise higher surfactant concentration with higher
ordered structures (such as liquid crystals). Such structured
layers can be opaque to naked eyes, or translucent, or clear. If
several structured layers are present, Hc is a sum of individual
structured layers. If any type of polymer-surfactant phase is
present, it is considered a structured phase and included in the
measurement of Hc. A sum of aqueous phases is Hs.
[0099] Finally, the structured domain volume ratio is calculated as
follows:
Structured Domain Volume Ratio=Hc/Hs*100%
[0100] If there is no benefit phase present, use the total height
as the surfactant layer height, Hs=Ha. The Structured Domain Volume
Ratio is the Lamellar Phase %. The measurement is made for each
dilution prepared and centrifuged (i.e., the Structured Domain
Volume Ratio is determined for the composition, and for 90%, 80%,
70% and 60% dilutions prepared as indicated above).
[0101] The highest amount of dilution (i.e., the lowest Dilution
Level) wherein the personal care composition maintains at least 95%
Lamellar Phase % is an indicator of amount of structure for
personal care compositions having varying n values for STnS.
[0102] The highest dilution wherein the personal care composition
has at least 95% lamellar phase is greater than about 15% , greater
than about 25%, or greater than about 35%.
[0103] The personal care composition has a Structured Domain Volume
Ratio of greater than about 40%, greater than about 45%, greater
than about 50%, greater than about 55%, greater than about 60%,
greater than about 65%, greater than about 70%, greater than about
75%, greater than about 80%, greater than about 85%, or greater
than about 90%, by volume of personal care composition comprising
an aqueous surfactant.
[0104] F. Lipid Particle Size Measurement
[0105] Lipid particle size is measured in neat product under a
differential interference contrast optical microscope with a
10.times. objective lens. The particle size distribution is counted
manually. All lipid particles are assumed as uniform spheres in
this application. For irregular shaped lipid particles, the longest
axis is used as the diameter for the particle size distribution
counting. The number weighted average of all lipid particles is
defined as the average lipid particle size.
[0106] G. In-vitro Deposition Method
[0107] In-vitro Deposition Evaluation Method: The In-vitro
Deposition Evaluation Method measures the deposition of benefit
agents on a skin mimic. The method compares the quantity of benefit
agent of the skin mimic surface before and after cleansing in an
automated cleansing unit, such as the automated cleansing unit
described in co-pending and co-assigned Multiphase Personal Care
Composition With Enhanced Deposition, U.S. application Ser. No.
12/510,880 (filed Jul. 28, 2009) and In-Vitro Deposition Evaluation
Method for Identifying Personal Care Compositions Which Provide
Improved Deposition of Benefit Agents, U.S. application Ser. No.
12/511,034 (filed Jul. 28, 2009).
[0108] The In-vitro Deposition Evaluation Method uses two 12-well
plates (hereinafter referred to as "plates"). Suitable 12-well
plates are commercially available from Greiner bio-one. For
example, the Cellstar.RTM. 12 well suspension culture plate has 3
rows and 4 columns with a well volume of about 6.2 mL. The
Cellstar.RTM. 12 well suspension culture plate comprises the
approximate dimensions of 19 mm in height, 127 mm in length and 85
mm in width. The Cellstar.RTM. 12 well suspension culture plate has
a well diameter of 23 mm, a well depth of 15 and a well to well
spacing of 2 mm A Cellstar.RTM. 12 well suspension culture plate is
provided for containing the samples comprising the personal care
composition in the Examples above.
[0109] The In-vitro Deposition Evaluation Method uses approximately
120 g of bodies for two plates. Five grams of bodies carefully
loaded into each of the 12 wells of the two plates to ensure the
same quantity is loaded into each well. Each body is a spherical
stainless steel bearing that is approximately 2 mm in
circumference. Each body comprises ferrometallic material. Suitable
bodies are those available from WLB Antriebeselemente Gmbh,
Scarrastrasse 12, D-68307 Mannheim, Germany.
[0110] The personal care compositions are prepared according to the
description in the Example Section above. After the examples of the
personal care compositions are prepared, control and test samples
are prepared by determining the dilution ratio and dispensing both
the personal care composition and distilled water into the wells of
the microplate and allow the samples to mix while being exposed to
the automated washing process. The dilution ratio used in this
application is one part of composition and twenty nine parts of
water (1:29). A pre-calibrated positive displacement pipette is
used to dispense 66.7 .mu.L of composition on to the bodies in each
well, followed by dispensing 1933.3 .mu.L of distilled water into
each well. The control samples and test samples are dispensed in
the specified wells of the plate, all within a 20 minute time
frame. Each composition is placed in 6 different well, 3 of which
are in plate 1 and the other 3 well are in plate 2. A test control
composition containing the benefit agent should be used in every
test to ensure consistency among tests.
[0111] The skin mimic used in the In-vitro Deposition Evaluation
Method is comprised of a molded bicomponent polyurethane substrate.
The skin mimic is textured on one side with a pattern that
resembles the texture of human skin. The textured side of the skin
mimic is coated with 1, 1, 1-trimethyl-1-pentene that is plasma
deposited. The skin mimic surface has a total surface energy of
32.+-.1.0 (mJ/m.sup.2) and a contact angle in water of
100.degree..+-.2.0. Suitable skin mimic surface materials are
described in co-pending and co-assigned Coated Substrate with
Properties of Keratinous Tissue, U.S Patent Pub. No. 20070128255A1
(filed Aug. 11, 2006) (published Jun. 7, 2007) and Methods of Use
of Substrate Having Properties of Keratinous Tissue, U.S Patent
Pub. No. 20070288186A1 (filed Feb. 5, 2007) (published Dec. 13,
2007).
[0112] After all of the wells of the plate are filled with the
samples and the pieces of skin are made and coated, the skin mimic
is prepared for the In-vitro Deposition Evaluation Method. Two
pieces of skin mimic are prepared by cutting the skin mimic to fit
on top of all 12 openings of the wells of the plate while wearing
gloves. The two pieces of skin mimic pieces are numbered "1" and
"2".
[0113] Next, the pieces of skin mimics are arranged over the
openings of the wells of the microplates. The pieces of skin mimic
surface material are transferred to cover the openings of the wells
of the each of the plates to ensure that the textured and treated
region of the skin mimic is facing the openings of the wells of the
plate. A lid is placed over each piece of the skin mimic and the
associated plate to form a lidded plate.
[0114] The lidded plates are placed into plate holders of an
automated cleansing unit, or, a device used in the in-vitro
Deposition Evaluation Method of the present invention. The
automated cleansing unit comprises a horizontal base comprising
four microplate holders. The horizontal base is made of rectangle
of aluminum comprising the following approximate dimensions of 3/8
inch in height, fourteen inches in width and twenty seven inches in
length. The automated cleansing unit further comprises two vertical
supports comprised of aluminum with the approximate dimensions of
one inch by two inches by ten and 3/4 of an inch in height. The
vertical supports are attached to a horizontal support comprising a
rodless air slide. The horizontal support comprising a rodless air
slide comprises the approximately dimension of a 1/2 inch by two
inches by twenty six and 1/2 inches in height. Suitable rodless air
slides comprise a one inch bore and eleven inch stroke and have
associated end lugs and mount brackets, which are commercially
available from McMaster-Carr. The rodless air slide can be double
acting and comprises a carriage that is connected to an internal
piston and two compressed air ports.
[0115] The automated cleansing unit comprises two magnetic arms.
The horizontal support comprising a rodless air slide is the
structure upon which the two magnetic arms are mounted. The
magnetic arms are mounted to the rodless air slide such that the
magnetic arms move back and forth along the length of the double
acting rodless air slide by the force of compressed air. Each of
the magnetic arms are comprised of aluminum and have the
approximate dimensions of one inch by two inches by fourteen inches
in length and have a "T" shape channel that houses seven neodymium
iron boron magnets (not shown). Each of the neodymium iron boron
magnets has the approximate dimensions of two inches in length, one
inch in width and half or an inch in height. Each of the neodymium
iron boron magnets comprises a magnetic strength of 12200 Gauss,
available from Edmund Scientifics. The magnetic arms are configured
at a height of about 2.75 cm above the microplate holder with the
caveat that the magnets maintain their function to attract and move
the bodies comprised within the wells of the microplate. The
magnetic arms move back and forth along the length of the rodless
air slide by the force of compressed air at a speed of
approximately 6 back and forth sweeps over the length of the
rodless air slide over a 10 second time period.
[0116] The magnetic arms can be configured with four microplate
holders. Each of the microplate holders comprise a clamping plate
and four pistons attached to a pneumatic control unit. When
actuated, the pistons for the pneumatic control unit hold the
plates in the four plate holders at a pressure of about 90 psi.
Prior to placing the lidded plates into the plate holders of
automated cleansing unit, the pneumatic control unit is turned
on.
[0117] The automated cleansing unit can comprise a pneumatic
control unit. The top view shows components of the pneumatic
control unit which can be connected to the rodless air slide, the
piston and clamping plates. The pneumatic control unit can be used
to apply compressed air to the automated cleansing unit, which
imparts a force by converting the potential energy of compressed
air into kinetic energy. The pneumatic control unit comprises a
solenoid air control valve, a distribution manifold outlet, a
compressed air control valve, a compressed air flow regulator, an
alternating output binary valve, a two-hand safety pneumatic
control valve, a compressed air control valve and various
connectors that provide pressurized air to the automated cleansing
unit from an external air source. The air control valve, air flow
regulators, alternating a binary valves, a two-hand safety
pneumatic control valve are positioned upstream of a solenoid air
control valve. A suitable solenoid air control valve can be
described as a double air style valve with a 10 psi to 120
operating pressure. Suitable compressed air flow regulators can
operate, for example, in the pressure range of 14 psi to 116 psi.
Suitable air control valve alternating output binary valves 40 can
operate, for example, in a 35 psi to 100 psi range. All of the
components of the pneumatic control unit are available from
McMaster-Carr.RTM..
[0118] The lidded plates are placed into the plate holders and
pneumatic control unit is actuated such that the lidded plates are
held under 90 psi of pressure. The magnetic arms are actuated on
and arms moves over the lidded microplates at a height of 2.65 cm
above the plate holders. The magnetic arms of the automated
cleansing unit, sweep back and forth over the plate holders for 5
minutes, at a speed of 6 sweeps per every 10 seconds. After 5
minutes of the automated cleansing process, the lidded plates are
removed from the plate holders and are disassembled.
[0119] After the automated washing process, two large 4000 ml
beakers of 20.degree. C. to 25.degree. C. water are filled. The
first piece of skin mimic is removed from the first plate and
submerged in the tap water within the first beaker five times. The
second piece of skin mimic is removed from the second microplate
and submerged within the second beaker five times. The completeness
of rinsing step is judged visually by the lack of foam on the skin
mimic and presence of defined circles of deposited material on the
skin mimic. Both piece of skin mimic are blotted gently with paper
towels and fumed in a drying hood for at least 3 hours each.
[0120] The cut-out pieces of treated skin mimic are then extracted
with a solvent and the extract is analyzed and quantified by gas
chromatography.
V. EXAMPLES
TABLE-US-00001 [0121] I: Personal Care Composition Base formula 1)
Aqueous Cleansing Phase Sodium Trideceth Ether Sulfate 8.63%
Cocamidopropyl Betaine 2.58% Trideceth-3 1.37% Sodium Chloride
4.45% Guar Hydroxypropyltrimonium Chlroide 0.45% (N-Hance CG-17
from Aqualon) Xanthan Gum 0.03% (Keltrol 1000 from CP Kelco)
Acrylates/C10-30 Alkylacrylate Cross Polymer 0.03% (Aqupec SER-300C
from Sumitomo) Methyl chloro isothiazolinone and methyl 0.04%
isothiazolinone (Kathon CG, Rohm & Haas) EDTA (Dissolvine NA
2x) 0.14% Sodium Benzoate 0.28% Perfume 1.25% Citric Acid, titrate
pH = 5.7 .+-. 0.2 Water and minors Q.S. 2) Lipid Phase A RBD
Soybean Oil 2.43% Glyceryl Oleate 0.025% BHT 0.05% 3) Lipid Phase B
Petrolatum 2.50%
[0122] The aqueous surfactant phase can be prepared through
conventional mixing technique. The order of addition is as follow
in the mixing vessel: water, sodium chloride, sodium trideceth
sulfate, cocamidopropyl betaine, trideceth-3, guar hydroxypropyl
trimonium chloride, Xanthan gum, Acrylates/C10-C30 Alkylacrylates
cross polymer, EDTA, sodium benzoate. Adjust pH to 5.7 with citric
acid. Then add Kathon and perfume. Keep mixing until homogenous. A
benefit phase comprising a high viscosity benefit agent is placed
into a separate tank and heated to between 50.degree. C. to
80.degree. C. (or above its melting point, whichever is greater).
An additional benefit phase comprising a low viscosity benefit
agent is placed into a second tank and heated to 20.degree.
C.-60.degree. C. (or above its melting point, whichever is
greater). Once the components of the cleansing phase are mixed, one
of the benefit phases is added to the cleansing phase by injecting
the benefit phase into a mixing device such as a static mixer,
rotor-stator device, recirculation loop, or into a mixing zone in a
mix tank, with the cleansing phase. The remaining benefit phase is
then added to the composition in a fashion similar to that of the
first benefit phase.
[0123] A sample process diagram for a manufacturing method is shown
in FIG. 1.
[0124] The order of addition of the phases and the mixing is
changed as noted below for each example.
[0125] Changes to this manufacturing method for each example are
listed below.
TABLE-US-00002 Example Example Example Example Example Example
Example Comparative 1 2 3 4 5 6 7 Example A II: Personal Care
Process Configuration Aqueous Aqueous Aqueous Aqueous Aqueous
Aqueous Aqueous Aqueous Cleaning Cleaning Cleaning Cleaning
Cleaning Cleaning Cleaning Cleaning Phase Phase Phase Phase Phase
Phase Phase Phase Infusion Infusion Infusion Infusion Infusion
Infusion Infusion Infusion Lipid B Lipid A Lipid A Lipid B Lipid B
Lipid A Lipid B Lipid A- Infusion Infusion Infusion Infusion
Infusion Infusion Infusion Lipid B Comined Preblend Infusion Lipid
A Lipid B 2-6 mm 2-6 mm 2-6 mm 2-6 mm 1-6 mm 2-6 mm Infusion
Infusion static static static static static static mixers mixers
mixers mixers mixer mixers 2-6 mm 2-6 mm Lipid B Lipid A Lipid A
Lipid B Lipid A 1-10 mm static static Infusion Infusion Infusion
Infusion Infusion static mixers mixers mixer 1-10 mm 1-10 mm 2-6 mm
2-6 mm 1-6 mm 1-6 mm 2-6 mm Salt Water static static static static
static static static Dilution mixer mixer mixers mixers mixer mixer
mixers Phase Infusion Salt Salt 1-10 mm 1-10 mm 1-10 mm 1-10 mm
1-10 mm 2-10 mm Water Water static static static static static
static Dilution Dilution mixer mixer mixer mixer mixer mixers Phase
Phase Infusion Infusion 2-10 2-10 Salt Salt Salt Salt Salt mm mm
Water Water Water Water Water static static Dilution Dilution
Dilution Dilution Dilution mixers mixers Phase Phase Phase Phase
Phase Infusion Infusion Infusion Infusion Infusion 2-10 mm 2-10 mm
2-10 mm 2-10 mm 2-10 mm static static static static static mixers
mixers mixers mixers mixers Petrolatum 272 .mu.g/ 272 .mu.g/ 295
.mu.g/ 301 .mu.g/ 315 .mu.g/ 349 .mu.g/ 330 .mu.g/ 70 .mu.g/
Deposition cm2 cm2 cm2 cm2 cm2 cm2 cm2 cm2
[0126] In the above table, the static mixers used were either six
or ten mm in diameter, as indicated. Each static mixer unit
consisted of six elements. The static mixers used were either one
or two units of mixers for a total of six or twelve mixing
elements. The static mixers used were SMX style static mixers from
Sulzer.
[0127] It should be understood that every maximum numerical
limitation given throughout this specification includes every lower
numerical limitation, as if such lower numerical limitations were
expressly written herein. Every minimum numerical limitation given
throughout this specification will include every higher numerical
limitation, as if such higher numerical limitations were expressly
written herein. Every numerical range given throughout this
specification will include every narrower numerical range that
falls within such broader numerical range, as if such narrower
numerical ranges were all expressly written herein.
[0128] The dimensions and values disclosed herein are not to be
understood as being strictly limited to the exact numerical values
recited. Instead, unless otherwise specified, each such dimension
is intended to mean both the recited value and a functionally
equivalent range surrounding that value. For example, a dimension
disclosed as "40 mm" is intended to mean "about 40 mm."
[0129] Every document cited herein, including any cross referenced
or related patent or application and any related patent or
application identified in the Application Data Sheet accompanying
this application, is hereby incorporated herein by reference in its
entirety unless expressly excluded or otherwise limited. The
citation of any document is not an admission that it is prior art
with respect to any invention disclosed or claimed herein or that
it alone, or in any combination with any other reference or
references, teaches, suggests or discloses any such invention.
Further, to the extent that any meaning or definition of a term in
this document conflicts with any meaning or definition of the same
term in a document incorporated by reference, the meaning or
definition assigned to that term in this document shall govern.
[0130] While particular embodiments of the present invention have
been illustrated and described, it would be obvious to those
skilled in the art that various other changes and modifications can
be made without departing from the spirit and scope of the
invention. It is therefore intended to cover in the appended claims
all such changes and modifications that are within the scope of
this invention.
* * * * *